This application responds to PA-03-107 (NIH Exploratory/Developmental Grant Awards). Using this R21 mechanism, we have an innovative opportunity to develop the nation's only dental practice-based research network, which is called the "Alabama Dental Practice Research Network (ADPRN)". Following unusually promising enrollment success to date, we propose two specific aims for this developmental phase. Specific Aim 1 is to enhance the infrastructure and research capacity of the network. This aim will be accomplished by enhancing the administrative structure of the ADPRN, by providing fundamental training in clinical research and human subjects precautions to network dentists, and by providing a communication infrastructure for network practices and the ADPRN administration, which will include an internet-based system. Specific Aim 2 is to conduct a feasibility study to test data collection methods for a retrospective cohort study that will ultimately test the hypothesis that endodontic treatment (root canal) failure is significantly higher among dental patients with diabetes mellitus type 2 when compared to non-diabetic controls. Building upon our enrollment success and experiences with the ADPRN thus far, funding this developmental phase would allow us to bring to fruition a practice-based research network whose mission is "to improve oral health in Alabama by conducting dental practice-based research and by serving Alabama dentists through education and collegiality". Our 101-item enrollment questionnaire provides exceptionally strong evidence that ADPRN dentists have a great deal in common with dentists nationally. The feasibility study would provide a sound scientific foundation for an R01 application to investigate the potentially bi-directional relationship between diabetes mellitus type 2 and endodontic treatment failure, allowing us to determine whether diabetes contributes to poor endodontic healing, and whether inadequate endodontic healing can itself contribute to poor diabetic control. In addition to developing the nation's first dental practice research network, we would link its development to the dental school's overall research infrastructure development and to the school's research curriculum development (two other recent major NIDCR initiatives), creating an innovative whole that is greater than the sum of its parts.